The present invention relates to a method of manufacturing a dental prosthesis to be implanted in a jaw of a patient and an appliance used for such an implantation.
Implants are at the moment positioned in four ways:
1. Freehand with a wide cut in the gum and detachment of the latter. Fitting takes place in an archaic manner without any reference or guiding mark with respect to the future prosthesis. Although this technique is the worst and gives results that are often aesthetically, functionally and hygienically disastrous, it is the most widely used. It is also the one that causes the most accidents (rupture of the mandibular nerve, piercing of the sinus, rupture of the cortices, etc).
2. Freehand with a wide cut in the gum and a detachment of the latter, the positioning takes place in a more or less precise manner since the dental laboratory has produced a surgical guide that more or less prefigures the future prosthesis. This technique is the second most widely used but the drawback is that the surgical guide is often unusable because of the cutting of the gum, which prevents the fitting thereof. With this technique there are also often poor results at an aesthetic, functional or hygienic level and accidents as aforementioned are numerous.
3. With the hand guided by drilling guides produced from a computerised plan. This technique makes it possible to place drilling cylinders in these guides at precise points according to the bone or according to the bone and the future prosthesis. Two distinct technologies apply this technique:                Guides are produced from steriolithographic models, that is to say on the basis of images issuing from dental scanning. Artefacts often interfere with the production of these guides not always making it possible to use them through lack of precision.        Guides are produced from an impression and a radiological guide that is produced on the basis of this impression in silicone (rather than on the basis of an image issuing from dental scanning). This radiological guide is then converted into a surgical guide by the insertion of guide cylinders for the drilling and the positioning of implants in the jaw.        
These techniques make it possible to reduce damage to the patient and in particular the last technique improves the prosthetic result.
4. Freehand guided by a navigation system (GPS). This technique makes it possible to place an implant more or less precisely. However, it does not prevent all damage to the patient since the drilling is still manual and skidding remains possible. In addition it does not take account of the future prosthesis. This technique is expensive and is the least used.
All these techniques together have the drawback of having to produce the final prosthesis after taking an impression of the jaw where the implants were placed previously, which is carried out several weeks after the positioning of the implants, which is complex and requires many post-operative interventions, which are difficult for the patient.